diff --git a/compiler/optimizing/code_generator_arm64.cc b/compiler/optimizing/code_generator_arm64.cc
index 72ca927..4092858 100644
--- a/compiler/optimizing/code_generator_arm64.cc
+++ b/compiler/optimizing/code_generator_arm64.cc
@@ -57,7 +57,7 @@
 #error "ARM64 Codegen VIXL macro-assembler macro already defined."
 #endif
 
-namespace art {
+namespace art HIDDEN {
 
 template<class MirrorType>
 class GcRoot;